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pleurotustoday at 7:26 AM1 replyview on HN

Thanks for the explanation! It makes a lot of sense that voxels would scale as badly as they do, especially if you want to increase resolution. Am I right in assuming that the reason this scales a lot better is because the Gaussian splats, once there's enough "resolution" of them, can provide the estimates for how light works reasonably well at most distances? What I'm getting at is, if I can see Gaussian splats vs voxels similarly to pixels vs vector graphics in images?


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teltoday at 11:25 AM

I think, yes, with greater splat density—and, critically, more and better inputs to train on, others have stated that these performances were captured with 56 RealSense D455fs—then splats will more accurately estimate light at more angles and distances. I think it's likely that during capture they had to make some choices about lighting and bake those in, so you might still run into issues matching lighting to your shots, but still.

https://www.realsenseai.com/products/real-sense-depth-camera...

That said, I don't think splats:voxels as pixels:vector graphics. Maybe a closer analogy would be pixels:vectors is the same as voxels:3d mesh modeling. You might imagine a sophisticated animated character being created and then animated using motion capture techniques.

But notice where these things fall apart, too. SVG shines when it's not just estimating the true form, but literally is it (fonts, simplified graphics made from simple strokes). If you try to estimate a photo using SVG it tends to get messy. Similar problems arise when reconstructing a 3d mesh from real-world data.

I agree that splats are a bit like pixels, though. They're samples of color and light in 3d (2d) space. They represent the source more faithfully when they're more densely sampled.

The difference is that a splat is sampled irregularly, just where it's needed within the scene. That makes it more efficient at representing most useful 3d scenes (i.e., ones where there are a few subjects and objects in mostly empty space). It just uses data where that data has an impact.